Carburetor Adjustment; The Air Filter - Homelite 150 Owner's Manual

CARBURET OR ADJ U STNilENT
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The carburetor was adjusted at the factory. lt is seldom
necessary to make major adjustments. Minor "triming"
is all that is usually necessary. Discourage all persons
from turning the adjustment needles experimentally. Ad-
justing the carburetor cannot restore performance lost
because of low compression, poor spark, or faulty fuel
defivery or air intake. In any evenl, always be sure the
air filter is clean, belore you make any carburetor adiust-
ments.
ADJUSTMENT IF ENGINE CANNOT BE
STARTED
With a small screwdriver, turn the Hl and LO mixture
adjustment needles slowly clockwise until both are
gently seated. (Careful! Forcing needle into seat can
rende-r carburetor unadjustable, requiring caburetor
replaiement.) Then turri the Ht ireedle ou-i 1 full turn
and the LO needle 3/+ lurn.
Latch the trigger for starting, and lololw instructions
lo start the saw. Unlatch the trigger to let the saw
idle. CAUTION: GHAIN WILL TURN WHEN ENGINE
STARTS AND MAY NOT STOP WHEN ENGINE IS
IDLED.
3. lf chain turns al idle throttle, turn lhe idle speed
screw slowly counterclockwise until the chain stops.
Now make linal adjustments as instructed below.
ADJUSTMENTS AFTER ENGINE IS AT
OPERATING TEMPERATURE
1. Run the saw for a few minules to get the engine
warm, then idle the engine and do the lollowing:
a) Turn the idle speed sclew clockwise until the
chain begins to turn. Note this screw setting.
+ts+
* b) Turn the idle speed screw in the other direction
until the engine starts to falter. Note this screw
' setting.
c) Set the idle speed screw midway between the set-
ings noted in a) and b).
2. ADJUST FOR PROPER IDLE: Adiustment ol both the
LOrcedte and the idle speed screw are required for
iiFe tuning of the iiiiiltiir5TThEl,o needie slowly
in one direction, then in the other, to find where the
engine idles the fastest on this temporary setting of
th;idle speed sciffiNOw, il this speed-is fastei or
slower than desired: if so fast thal the chain turns'
or so slow that lhe engine falters, change the idle
speed by readjusting the idle speed screw. THEN,
readjust the LO needle for lhe fastest idling at !!!9
idte speed screw setting. NOTE: for line tuning, lhis
sequence may need to be repeated several limes.
3, ADJUST Hl NEEDLE FOR MAIN OPERATION: With
bar and chain clear of all obstacles, turn the Hl needle
clockwise until the saw cannot accelerate flom idle
to wide open throttle at no load. Now turn the Hl
needle the other way, a little at a time, until the en-
gine accelerates smoothly lrom idle to wide open
throttle without a cutting load. IMPORTANT: Frqn
this point,turntheltffittanother
th turn oo*s
clockwise.
IDLE SPEED SCREW
1 .
The air filter should be removed and cleaned twice each
day of operation, or more frequently if extremely diriy
operating condilions are encountered. A dirty lilter
causes saw to run excessively rich, smoking exces-
sively, using luel at a fast rate and lacking in power.
Never attempt carburetor adiustment until the air filter
has been checked and cleaned or replaced.
1. Remove air intake cover (left rear side of saw) by
taking out the cover mounting screw. Glean sawdust
from air intake area ol saw belore removing the filter.
2. Clean filter by tapping it against a clean surface. Oc-
casionally, give it a thorough cleaning in a non'oily
cleaning solvent and let it dry befote further use.
Filters do not cost much so you may lind it practical
to keep a few spares on hand lor instant changing.
3. Cleaning does not remove all dirt particles lrom the
filter pores. Therefore, replace the lilter after several
months of use or more than 30 cleanings'